Low power, chip-based stimulated Brillouin scattering microwave photonic filter with ultrahigh selectivity

TL;DR

This paper introduces a novel chip-based microwave photonic filter utilizing stimulated Brillouin scattering, achieving ultra-high suppression, high resolution, and wide frequency tuning in a compact form, advancing integrated RF signal processing.

Contribution

First demonstration of a chip-based MWP band-stop filter with record suppression and tunability using low Brillouin gain and optical resonance-assisted RF cancellation.

Findings

Achieved ultra-high suppression in a compact chip-based filter.

Realized 0-30 GHz tunable frequency range.

Demonstrated high resolution in the MHz range.

Abstract

Highly selective and reconfigurable microwave filters are of great importance in radio-frequency signal processing. Microwave photonic (MWP) filters are of particular interest, as they offer flexible reconfiguration and an order of magnitude higher frequency tuning range than electronic filters. However, all MWP filters to date have been limited by trade-offs between key parameters such as tuning range, resolution, and suppression. This problem is exacerbated in the case of integrated MWP filters, blocking the path to compact, high performance filters. Here we show the first chip-based MWP band-stop filter with ultra-high suppression, high resolution in the MHz range, and 0-30 GHz frequency tuning. This record performance was achieved using an ultra-low Brillouin gain from a compact photonic chip and a novel approach of optical resonance-assisted RF signal cancellation. The results point to new ways of creating energy-efficient and reconfigurable integrated MWP signal processors for wireless communications and defence applications.